Animals Are 'Stuck In Time' With Little Idea Of Past Or Future
Time can be a hard concept for all of us. I've been watching a program on the Science Channel about time in the universe, time on earth, time in our lives. Perspective is everything. I thought this research about how animals use time was interesting.
Comedian George Carlin used to have a very funny bit in his comedy routine about dogs where he would talk about how dogs had no conception of time. He said something like it didn't matter to a dog if you left the house for five minutes or two hours, to a dog it was all the same. It felt like you were gone forever. I think that's true. Even if you leave the house for five minutes, your dog will be just as happy to see you when you come back in the house as if you've been gone for ages. I love them for that! If I just run to the grocery store I get the same enthusiastic welcome home as if I've gone to the moon and back. It really makes me feel good. I think it's because, to my dogs, I've been gone a long time and they are really glad to see me again.
The new study, described below, tried to learn how rats understood time. I don't know if dogs are the same. They may be more sophisticated in their understanding of time. But the research is interesting. If the same results are true for dogs (and I'm sure they will soon be testing dogs in similar ways), it could help us understand how dogs who have been lost for years can remember their owners and find their way home again when they have been lost hundreds of miles away.
From Science Daily.
Animals Are 'Stuck In Time' With Little Idea Of Past Or Future, Study Suggests
ScienceDaily (Apr. 7, 2008) — Dog owners, who have noticed that their four-legged friend seem equally delighted to see them after five minutes away as five hours, may wonder if animals can tell when time passes. Newly published research from The University of Western Ontario may bring us closer to answering that very question.
William Roberts and his colleagues in Western’s Psychology Department found that rats are able to keep track of how much time has passed since they discovered a piece of cheese, be it a little or a lot, but they don’t actually form memories of when the discovery occurred. That is, the rats can’t place the memories in time.
The research team, led by Roberts, designed an experiment in which rats visited the ‘arms’ of a maze at different times of day. Some arms contained moderately desirable food pellets, and one arm contained a highly desirable piece of cheese. Rats were later returned to the maze with the cheese removed on certain trials and with the cheese replaced with a pellet on others.
All told, three groups of rats were tested in the research using three varying cues: when, how long ago or when plus how long ago.
Only the cue of how long ago food was encountered was used successfully by the rats.
These results, the researchers say, suggest that episodic-like memory in rats is qualitatively different from human episodic memory, which involves retention of the point in past time when an event occurred.
"The rats remember whether they did something, such as hoarded food a few hours or five days ago,” explained Roberts. “The more time that has passed, the weaker the memory may be. Rats may learn to follow different courses of action using weak and strong memory traces as cues, thus responding differently depending on how long ago an event occurred. However, they do not remember that the event occurred at a specific point in past time.”
Previous studies have suggested that rats and scrub jays (a relative of the crow and the blue jay) appear to remember storing or discovering various foods, but it hasn’t been clear whether the animals were remembering exactly when these events happened or how much time had elapsed.
“This research,” said Roberts, “supports the theory I introduced that animals are stuck in time, with no sense of time extending into the past or future.”
The results of the research, entitled “Episodic-Like Memory in Rats: Is it Based on When or How Long Ago,” appear in the journal Science, April 4, 2008.
Adapted from materials provided by University of Western Ontario.
